1. Field of the Invention
The present invention relates to an electric wave axis adjusting apparatus for a radar mounted on a vehicle for adjusting an electric wave axis of an on-vehicle radar having a structure in which an electric wave is transmitted and an electric wave reflected by an obstacle is received, to thereby detect a position or the like of the obstacle.
2. Description of the Related Art
Heretofore, a radar mounted on a vehicle (hereinafter, referred to as “on-vehicle radar”) has been utilized for an obstacle approach warning system, a vehicle-to-vehicle distance control system, a traffic congestion following system, and the like.
However, if an electric wave axis (a central axis of an electric wave or a directivity axis) and a vehicle traveling axis are not aligned with each other when the on-vehicle radar system is fixed to a vehicle, an error occurs in an angle of a detected obstacle. As a result, there is a possibility that a vehicle traveling along an adjacent traffic lane is judged to be a precedingly traveling vehicle by mistake, or a precedingly traveling vehicle is not judged to be as such by mistake.
Then, a detection range adjusting system of an obstacle detection apparatus for a vehicle is known, in which a detection range for detection of a standard reflector is set to a range narrower than a scanning range for aligning an electric wave axis and a vehicle traveling axis with each other and the detection range is changed within the scanning range so that a detection position of the standard reflector installed in a predetermined position relative to a vehicle agrees with a standard position information stored in advance (refer to JP 09-178856 A for example).
However, the detection range adjusting system having the above construction involves a problem that since the detection range is set to the range narrower than the scanning range, a wasteful range occurs in which only the scanning is carried out and no standard reflector is detected.
In addition, there is also encountered a problem that it takes time to scan the range in which the reflector as the standard reflector is not detected, and thus a delay occurs in time for detecting the reflector to be normally detected.